Vertical interincisal trespass assessment in children with speech disorders.

Through a transversal epidemiological study, conducted with 333 Brazilian children, males (157) and females (176), aged 3 to 6 years old, enrolled in a public preschool, this study aimed to evaluate the prevalence of the different types of vertical interincisal trespass (VIT) and the relationship between these occlusal aspects and anterior lisping and/or anterior tongue thrust in the articulation of the lingua-alveolar phonemes /t/, /d/, /n/ and /l/. All children involved were submitted to a VIT examination and to a speech evaluation. Statistical significance was analyzed through the Qui-square test, at a significance level of 0.05 (95% confidence limit). The quantitative analysis of the data demonstrated the following prevalences: 1 - the different types of VIT: 48.3% for normal overbite (NO), 22.5% for deep overbite (DO), 9.3% for edge to edge (ETE) and 19.8% for open bite (OB); 2 - interdental lisping in relation to the different types of VIT: 42% for NO, 12.5% for DO, 12.5% for ETE, 32.9% for OB; and 3 - children with anterior tongue thrust in the articulation of lingua-alveolar phonemes in relation to the different types of VIT: 42.1% for NO, 14% for DO, 10.5% for ETE, 33.3% for OB. The results demonstrated that there was a significant relationship between open bite and anterior lisping and/or anterior tongue thrust in the articulation of the lingua-alveolar phonemes /t/, /d/, /n/ and /l/; and that there was a significant relationship between deep overbite and the absence of anterior lisping and anterior tongue thrust in the articulation of the lingua-alveolar phonemes.